Material drying and conveying apparatus



April 29, 1969 REUTER ET AL 3,440,733

MATERIAL DRYING AND CONVEYING APPARATUS Filed Dec. 7', 1967 Sheet of 2'W I40 I it 141 32A BR/AN R REUTER 5 TUA R7 5 TEFPN INVENTORS BY 21/5 6,M

ATTOR/Vf) April 29, 1969 B, R, REUTER ET AL 3,440,733

MATERIAL DRYING AND CONVEYING APPARATUS Filed Dec. 7, 1967 Sheet i of 2I 4./ 96a? 96 9m 5/a A 4! HL.-l)/

//a 2568/ I/6/ it 1 i 72 &

BR/A/v R R541 75/? STUART STERN [NVENTORS BY 2J5 5,214-

A TTORNE Y United States Patent 3,440,733 MATERIAL DRYING AND CONVEYINGAPPARATUS Brian R. Renter, Houston, Tex., and Stuart Stern, Fort Lee,N.J., assignors to Consolidated Engineering Comprany, Inc. (CECO),Houston, Tex., a corporation of exas Filed Dec. 7, 1967, Ser. No.688,801 Int. Cl. F26b 3/08, 17/12 US. C]. 3410 12 Claims ABSTRACT OF THEDISCLOSURE As a primary object the invention sets out to provide a meansfor automatically controlling the cyclic measured entry, drying whileback-filtering, activating, full discharging and purge discharging of amaterial which enters the processing pump, vessel, or container, theentering material having a moisture content which is removed by dryingas the material is rendered fiowable by a pressurized activating anddischarging gas.

It is also an object of this invention to provide apparatus of thisclass which is selectively set to automatically control fill, drying,activation, full discharge and purge discharge, or alternately, when thehandled material does not have to be dried, to automatically control,fill, activate, full discharge and purge discharge.

It is still a further object of this invention to provide apparatus ofthis class which additionally provides a safeguard to close the fillvalve in case the regularly provided fill valve closing means should notfunction, or fail to function timely.

It is also another object of this invention to provide apparatus of thisclass which may dry the handled material by interspersin-g predeterminedfilter blast periods between predetermined drying intervals betweenblasts.

Other and further objects will be apparent when the specification hereinis considered in connection with the drawings, in which:

FIG. 1 is an elevational view, part in section, of a container, pump orpressure vessel, partially diagrammatical, which discloses an embodimentof the invention;

FIG. 2 is a sectional bottom view, looking upward along line 22 of FIG.1;

FIG. 3 is an electrical diagram of the apparatus and circuitry therefor,as employed in actuation of the apparatus disclosed generally in FIG. 1;and

FIG. 4 is an isometric view of safeguarding apparatus indicated in FIG.1, with a circuit diagram of the circuitry entering into its operation.

Referring now to the drawings in which like reference numerals areapplied to like elements in the various views, a material container,housing, pump or activator is shown in FIG. 1 comprised of a shell 11including a cylindrical main body 11a with upper end closed by a topcomprised of a spherical segment or dome 12a and a bottom comprised of aspherical segment or lower closure 12b, the container being constructedafter the general 3,440,733 Patented Apr. 29, 1969 ice manner ofconventional pressure vessels, and designed with safety factors, towithstand the highest pressures that may be developed therein.

The pressure vessel or container 10 is supported on legs 14 whichupstand from a conventional base or grout, not shown. A gas permeablemembrane or diaphragm 13, sloped at substantially 13 degrees, asindicated, separates the container into an upper, or material plenum 15,and a lower, or gas plenum 16.

The dome 12a has an inlet flange or neck 17 connected centrally into thetop thereof with an inlet gate valve or fill valve 18 being mountedthereon. The top flange 19 of the fill valve 18 is shown connecting thefill valve 18 with a discharge flange 20 from a hopper 21.

A valve operator 23 is shown diagrammatically, as disposed to open andclose the gate valve 18, a piston 23a being shown provided in the valveoperator 23, with instrument air admissable under the piston 23a througha conduit 23b to open the fill valve, and with instrument air beingadmissable through a conduit 230 above the piston 23a to close the fillvalve. Obviously, the conduits 23b and 230 must be in a closedcompressed circuit with a pressurized reservoir, or otherwiseselectively supplied with compressed air, to carry out their respectivefunctions.

A hot drying gas conduit 107 is shown connected into the lower endclosure 12b of the shell or pressure vessel 11 below the high side ofthe membrane 13, and such hot drying gas inlet line 107 has a drying gasvalve 26 therein, which is shown connected to be opened and closed by avalve operator 27, constructed and equipped in correspondence with thevalve operator 23. Also, a discharge outlet pipe 28 extends downwardlythrough the dome 12a to terminate in a pick-up end 28a disposed slightlyabove the low side of the gas permeable or air permeable membrane 13. Avalve 29 is shown connecting this discharge outlet pipe 28 with adischarge conduit 30. The discharge valve 29 is shown operated by avalve operator 33, which is indicated as being constructed, and ashaving connections thereto, in correspondence with the fill valveoperator 23.

A purge line 34 extends between the discharge conduit 30, downstream ofthe discharge valve 29, to the material plenum or chamber 15 and has apurge valve 35 thereln to control its opening and closing, a valveoperator 36 being shown connected to the purge valve 35 for thispurpose, such valve operator 36 being constructed, and havingconnections in correspondence with the fill valve operator 23. However,it may be pointed out, in this regard, that the purge valve 35 should bea normally open valve, whereas the fill valve 18, gas lnlet valve 26,and discharge valve 29 are normally closed valves.

Additionally, the support body 37 for a safeguarding vibratory paddle38, operative on the tuning fork principle, is shown connected into thecylindrical body 11a of the shell 11, the material sensitive paddle 38being indicated in dotted lines in FIG. 1 as extending within thehousing 10 near the top thereof, such paddle being operative to actuatethe valve operator 23 to close the fill valve 18, as will be hereinbelowdescribed.

An insulative cord 39, having therein the electrical conduits to thepaddle 38, extends from the paddle support body 37 to a control box 40,to be hereinbelow described, and shown mounted on the exterior of theactivator shell body 11a.

A vent valve 31 is shown connected into the dome 12a in FIG. 1 andoperated by a valve operator 32 which is constructed, and hasconnections thereto, in correspondence with the fill vale operator 23.Also a solenoid operated blast air valve 104 is shown connected into thedome 12a oppositely of the vent air valve connection, with blast air, tobe hereinbelow described, being supplied to the valve 104 through ablast air conduit 105. Additionally, a solenoid operated, transfer ormoving air valve 106 is connected into the shell bottom 12b or gasplenum chamber 16, a conduit 25 being connected to supply moving air tothe valve 106. Also, the shell segment 12b is shown having a drain valve108 connected into the bottom thereof. Also, a conventional manhole 109is shown provided in the side of the shell cylinder 11a.

The neck or nipple 17 which supports the fill valve 18, and by means ofwhich the valve 18 is connected to communicate through the top of thedome 12a, extends downwardly into the shell or vessel 11 as indicated inFIG. 1. A series of equally angularly spaced apart, radially extendingsupport rods or bars 110 have their inner ends connected to the nipple17 and are connected at their outer ends to the inner surface of theshell 11a, as best seen in FIG. 2. At a spaced distance below thesuspension bars 110 a baffle plate 111 extends across the shell 11a andhas a central enlarged opening 12a therein into which is connected thelower end of a central perforated sleeve 112 of frusto-conical shape,the upper end of the sleeve 112 being affixed to the outer periphery ofthe lower end of the nipple 17.

A ring of round or eliptical holes or openings 113 is provided in thebaffle plate 111, the hole being equally angularly spaced apart, andsuch holes receive therein the lower ends of perforate filter sleeves114 to be affixed to the battle plate 111. The filter sleeves 114 are ofreduced cross-sectional area upwardly and the top of each sleeve 114 isconnected upwardly to a respective suspension bar 110 as best indicatedin FIG. 1. The filter sleeves 114 may be of woven metal cloth, perforateglass or perforate plastic of such porosity to admit the processing gasor air to pass therethrough while entraining or stopping the passage ofthe process material. A suitable handhole 115 is shown provided in FIG.1 for access to the filter sleeves 114 and central sleeve 112. It shouldalso be noted in the bottom view of FIG. 2 that the relative positionsof the blast air inlet 104a and the vent air outlet 31a are discernible.

As shown in FIG. 3, a positive line 41 and a negative line 42 extendfrom a source of electrical power, the positive line 41 having threeparallel lines 41a, 41b and 410 branching therefrom with the line 41aserving when manual control is to be used as will be hereinbelowdescribed with the line 41b serving as a neutral third positiveconductor and with the line 41c serving as the positive conductor whenautomatic control is to be employed. A three-way switch, indicatedgenerally by reference numeral 44, is provided to control the selectionof automatic or manual control, as desired, and as shown, the switch 44indicates that automatic control has been selected, the conductors 41b,410 thus being closed and the conductor 41a being open.

A conductor 45 extends from the conductor 41c, and a push-button switch45a is shown in FIG. 3 as closing circuit in this conductor, theconductor 41c continuing to a junction with three parallel circuitsincluding the circuit of a variable time delay relay 46, the circuit 47for a solenoid 48 which operates the fill valve operator 23 shown inFIG. 1, and the circuit of an indicator light 4 9 which may bedesignated as a green light for illustratwo purposes.

The conductor 45 continues as the conductor 45c and has contacts 51::therein of a double acting pressure actuated switch 50, such contacts51a being normally closed at atmospheric pressure and opening uponincrease of pressure in the gas plenum 16. The conductor 45c continuesfrom the contacts 51a to a junction with a conductor 45b having thereinthe normally closed relay contacts 56a of a latching relay 52., theconductor 45b terminating at its connection to the negative power line42.

A parallel circuit 53 extends from the neutral or central positiveconductor 41b, to the junction of the conductors c, 45b, such parallelcircuit also including themin the contacts 51b of the aforesaid pressureactuated switch 50, such contacts 51b being normally open at atmosphericpressure and closing upon increase of pressur in the aforesaid gasplenum 16. The circuit 53 also has therein an indicating light 54,designated as a yellow light for indicating purposes, as will behereinbelow described.

Another parallel circuit 55 from the positive conductor 41b has theswitch 46a therein which is closed by the variable delay relay 46 at theend of its preselected cycle, the circuit 55 also having therein thecoil 52a of the latching relay 52, and the circuit 55 being continued bythe circuit 450, as aforesaid. The circuit 55, as thus closed, energizesthe latching relay coil 52a to open the normally closed relay contacts56a to break the aforesaid parallel circuits 46, 47, 49 and 55, and uponthe solenoid circuit 47 being de-energized, the solenoid 48 retracts andmoves the valve operator 23 to close the fill valve 18, both valveoperator and fill valve being shown in FIG. 1.

The latching relay 52 is of the well known type, which, when its coil52a is energized, it actuates conventional switching means which opensthe normally closed contacts 56a, and pulls closed the normally opencontacts 56b in a parallel circuit 57 extending from the negativeconductor 42, in manner that the latching relay mechanism latchesagainst any movement except that which may be imparted to the switchingmeans to pull open the normallyopen contacts 56b, which can only beetfectuated by the energization of the latching relay coil 52b, to behereinbelow described as to operation.

The apparatus for handling a material not requiring drying will be firstdescribed, for purposes of clarity, and with its operation understood,the apparatus for interjecting the drying processes will then bedescribed, and the relationship to the activating, full discharging andpurge discharging apparatus and steps set forth therewith.

The circuit 57, hereinabove referred to, has the aforesaid latchingrelay, normally open contacts 56b therein, and adjacent thereto, indirection of the positive conductor 41b, 2. manual throw switch 69 isconnected into the circuit '57, so that when the switch 60 is manuallyor selectively disposed to connect the circuit 57 with a continuationcircuit 57a, the apparatus is set to handle a material which does notrequire a drying process before delivery for subsequent handling. Thusthe four circuits:

57b, and then 59, 61 and 62, to be hereinbelow described, are joined tothe circuit 57a, the circuit 57b being continued by the circuit 570 tothe positive conductor 41b.

From the junction of the circuits 57b, and 570, a circuit 64 a having aswitch 64 therein, continues as the circuit 64b to the negative sidejunction of the aforesaid circuits 59, 61 and 62. A fixed time delayrelay 58 of the thermal delay type, in the circuit 57b, operates for itstime interval, when the circuit 57a is closed, and closes the switch 64whereby the solenoid 59a in control box 40 releases air from the tube127 to open the moving air inlet valve 106 whereby the circuit includingthe light 61, blue to indicate activation, is closed, and whereby thecircuit 62 actuates the solenoid 63 to close the purge valve 35; seeFIGS. 1, 2 and 3.

Also, a circuit 57d continues from the junction of the circuits 57b, 59,61 and 62 with the circuit 57a, and branches into: a circuit 65including the coil which operates a solenoid 66 which actuates the valveoperator 33, shown in FIG. 1, to open and close the discharge valve 29;a circuit including a light 67 therein, which is designated as a redlight, for purposes of illustration; and a circuit having a relay 68therein; from the positive side junction of the circuits 65, 67 and 68,there extends a circuit 57e (having a normally open pressure actuatedswitch 69 therein, to be hereinbelow described), with its positive sideconnection being completed with the conductor 41c; and there alsoextends from such junction a circuit 57f having a pair of contacts 70therein operated by the relay 68, and terminating by connection with theneutral or positive conductor 4112. A push-button switch 71 is shown inFIG. 3 closing the circuit 41c adjacent its connection to the circuit-57e.

Additionally, a circuit 72b, 72a connects the positive or neutralconductor 410 with the negative power line or conductor 42; the circuit72b having in series therein a pair of contacts 74, (operated by therelay 68 substantially simultaneously with its operation of the contacts70 in the circuit 57 and a pressure sensitive switch 73 which functionsas will be hereinbelow described. Then, the circuit 72a, with which thecircuit 721) connects, has therein the latching relay coil 52b whichoperates to break circuit closed by the hereinabove described relaycontacts 56b.

The gas, as compressed air, which activates and transports the materialwhich enters the container, shell, or pressure vessel 11, arrives fromits source, as a compressor or pressure header 25h, as shown in FIG. 1,and enters conduit 25 to pass through a strainer 83 and a globe valve 84on its way to being regulated as to the pressure at which it is to besupplied. Thus the gas is first measured by a high pressure gauge 85 inthe top of a gauge pipe 85a which upstands from the main gas line 25through which the strained gas passes on downstream, and to the transfergas valve 106.

A smaller sized by-pass line 25a extends between the gauge pipe 85a andthe aforesaid pressure regulating valve 86 in the main conduit 25, andhas a pilot regulating valve or regulator 87 therein, thus to permit afiner and more responsive control of the pressurized gas on its way tothe pressure vessel 11. A by-pass line 87a conveys the reduced pressuregas from the pilot regulator 87, and connects with an upstanding gaugepipe 88 above the main conduit 25, a low pressure gauge 89 being mountedon top of the gauge pipe 88 to indicate the lowered pressure of the gas.

A conduit 90 extends from the lower closure 12b to conduct pressurizedgas from the gas plenum 16 to the control box 40, there to bear upon andcause actuation of the pressure sensitive switch 50, operative ashereinabove described, and to bear upon and cause actuation of pressuresensitive switches 69 and 73, to be further described as to operationhereinbelow.

The switch actuating gas, which must be taken from within the pressurevessel 11, enters the conduit 90 and passes through a strainer 91therein, and on to the panel box 40, a gauge 92 being provided toindicate the pressure of the actuating gas as it passes downstream ofthe strainer 91 on its way to the panel box pressure sensitive switches,as aforesaid. The instrument air required by the pressure sensitiveswitches, as contradistinguished from the actuating air or gas, and anyother air or gas required to actuate any of the apparatus, as thatrequired to operate the valve operators shown in FIG. 1, may be broughtto the panel box 40 through a conduit 93 for selective distribution.

Also, the power conductors 41, 42, from a source of electrical power, asa 60 cycle, 115 AC. voltage source. may be brought to the panel box 40through an insulated conductor cord 95. A conventional fuse 96 isprovided in the positive power line 41, indicated as comprising theconventional fuse strip 96a, and in a parallel circuit therewith, theconventional resistance 96b and indicating light 960.

The operation of the apparatus shown in FIGS. 1, 2 and 3 may be setforth in a sequence, and partially by way of reiteration, with thecomposite switch contacts 51a and the latching relay contacts 56aclosed, the switch 45a may be manually closed whereby the solenoid 48actuates its associated valve operator to open the fill valve, as thevariable time delay relay 46 starts its cycle and times out as it closesthe switch 46a at which time the relay 52a of the latching relay isenergized to break the latching relay contacts 56a and close thelatching relay is energized to break the latching relay contacts 56a andclose the latching relay contacts 56b, the fill valve 18 thus beingclosed. The switch arm 60 closes circuit with the circuit 57a, and thefixed time delay relay 58 is energized so that the switch 64 is closedand the solenoid 59a actuates its associated valve operator to open theactivating air or gas valve 106 to let gas, such as compressed air, intothe gas plenum 16 to pass through the membrane 13 and into the materialplenum 15 to start pressurizing the vessel or activating the material tobe transferred. Also, as this occurs, the circuit 62, having therein theswitches 62a, 6217 on either side of the solenoid windings 62, incircuit closed position, the energized solenoid windings 62 actuate thesolenoid 63 to actuate the valve operator 36 to close the purge valve35. This pressurizes the vessel 10 and activates the material until thatpressure is attained which will close the normally open pressureactuated switch 69 whereby the solenoid 65 is actuated to move itsassociated valve operator 33 to open the discharge valve 29. Also therelay 68 is energized to close the normally open switch 70 and thenormally open switch 74.

Discharge then continues until the pressure drops to open the pressuresensitive switch 69, then to close the pressure sensitive switch 73,thus completing circuit to the latching relay coil 52b which isenergized to open the latching relay contacts 56a, thereby to close thelatching relay contacts 56b whereby the windings of the dischargecontrol solenoid 66, of the activating air control solenoid 59a, and ofthe purge control solenoid 63 are de-energized, so that discharge valve29 and air supply valve 26 are closed and the purge valve 35 is opened.The vessel then purges itself until the pressure falls substantially toatmospheric to close switch contacts 51a and open switch contacts 51b,thus returning the apparatus to initial status.

Also, a fail-safe or safeguarding, material sensitive, frequency changeactuated, control assembly 37 is provided to insure the closing of thefill valve 18 in case the variable time delay relay 46 may not functionto close the time-out switch 46a at the end of the time cycle periodselected, as indicated diagrammatically in FIG. 3, and as shownpartially diagrammatically and in greater detail in FIG. 4.

The fail-safe circuit is shown extending from a point on the conductor55 between the time-out switch 46a and the latching relay coil 52a, andis continued to a solids state relay housing 98, there to be connectedto the junction between a conduit 75a to the normally open side of arelay switch 97, and a circuit 76 which extends to the positiveconductor power line 41a, the circuit 76 having the push-button switch77 therein, to be hereinbelow described. Normally, the relay switch 97closes contact between a grounded conductor 97a (and thus the negativepower line side 42) and a conductor means 99 between the relay switch 97and the negative terminal of a coil 82 in the control housing 37.

The coil 82, within the housing 37, is indicated externally thereof byits connections 82a, 82b which terminate within the plug 98. Within thehousing 37 the coil 81 energizes a plunger or armature, not shown, inmanner that it normally vibrates cycles per second to impart vibrationat this frequency to the lower tuning fork tine 38av which is shownconnected in FIG. 4 to the paddle or vibrator 38. Thus normally the tine38b also vibrates with the paddle 38 at 120 cycles per second. Thevibrations of the tine 38b are imparted to an armature, not shown, whichnormally actuate a second coil 81, at an imparted voltage, 60 cycles persecond frequency. Such coil 81, also not shown within the housing 37, isindicated externally thereof in FIG. 4 by its connections 81a, 81b,which terminate within the plug 98.

An induction coil, not shown, is imposed across the terminals of thecoil 81 within the plug so disposed with relation to the switch 97 thatthis switch may be shifted when the differential between the linevoltage and the imparted voltage achieves a certain value, as is thecase when material entering the container or activator 10 extends atsuch an angle of repose to interfere with, reduce, or stop thevibrations of the paddle 38.

When the aforesaid induction coil across the terminals of the coil 81thus shifts the switch 97 to close circuit from the neutral or positiveside conductor 41b, by way of the conductor 78, the coil 82, and theconductor 99, through the switch 97, as thus shifted, and by way of theconductors 75a, 75, 55 (including the latching relay coil 52a), and onthrough the conductor c, the closed switch contacts 51a, and the circuit45b (including the latching relay closed contacts 56a), to the negativepower line 42. The energization of the latching relay coil 52a in thecircuit results in the latching relay breaking the circuit 45b byshifting open the contacts 56a, whereby the solenoid winding 47 isde-energized to actuate the solenoid 48 to operate the valve operator 23to close the fill valve 18.

Obviously the quicker the fail-safe switch 97 is operated after afailure of the variable time delay relay 46 to close the time-out switch46a, the less the material from the hopper 21 can over fill thecontainer 10, and the closer the delivered batches of material may becontrolled to deliver a desired lesser volume per batch.

Also, it is obvious that the variable time delay relay 46 may be omittedentirely, together with its time-out switch 46a, and in this case thefrequency control device 37 alone can be relied upon to actuate thevalve operator 23 to close the fill valve 18.

On occasion it may be desirable to operate the filling and evacuation ofthe container 10 by manual control of the sequence of steps, rather thanautomatically, as hereinabove described. For such occasion, it may beconsidered that the variable time delay relay 46 and its timing outswitch 46a are immobilized. Then a circuit 101 is provided, parallelwith the circuit 45, to extend from the positive conductor 41a and toconnect with the circuit 45 between the pushbutton 45a and the circuitjunction 46, 47, 49. Also in this case, there also serves the aforesaidcircuit 76 from the circuit 41a to the junction of circuits 75, 75a, andhaving the pushbutton 77 therein; also, the circuit 102, parallel withthe circuit 57c and connected thereinto between the pushbutton 71 andthe normally open pressure sensitive switch 69; also, the positive powercircuit 41a is extended to connect with the junction of the circuits72a, 72b, and to have the pushbutton 103 therein.

Thus, with the three-way switch controlling the parallel conductor lines41a, 41b and 41c turned from the position shown in FIG. 3, in mannerthat the conductors 41a, 41b are closed, the conductor 410 thus beingleft open. Beginning with the container 10 empty and at atmosphericpressure, the pushbutton 45a may be pushed downwardly and held to closethe circuit 101. The circuit 47 is thus energized so that the solenoid48 actuates the valve operator 23 to open the fill valve 18. Then, thepushbutton 45a may be released from closing the circuit 101, thusbreaking circuit through the solenoid coil 47 so that the solenoid 48actuates the valve operator 23 to close the fill valve 18.

With a batch of material delivered into the container 10 in amountdetermined by the length of time the pushbutton 45a has closed thecircuit 101, activation of the material may be started, after thepushbutton 45a has been released, by manipulating the pushbutton 77 toclose the circuit 76. Circuit is thus closed through the circuit 75, thecircuit 55 including the latching relay coil 52a, and to the negativepower line side 42, by way of circuit 450, closed contacts 51a of thepressure sensitive switch 50, and the circuit 45b, including thelatching relay closed contacts 56a therein. This energizes the latchingrelay coil 52a to operate the latching relay 52 to break the contacts56a and close the contacts 56!).

Circuit is thus closed to the fixed time delay relay 58,

which actuates the time out switch 64 to close the solenoid coil circuit59, thus to actuate the valve operator 27 to open the compressed airvalve 26; also the solenoid coil circuit 62 is closed whereby thesolenoid 66 actuates the valve operator 36 to close the purge valve 35.

Then, the operator of the apparatus may observe the gauge 92, and whenthe pressure indicates that the vessel is ready to discharge, or whenthe operator appreciates that a proper time interval after the openingof the gas inlet or compressed air valve 26 has taken place, thepushbutton 71 may be pushed to close the circuit 102,

the normally open pressure sensitive switch 69 being closed by thepressure that has built up in the vessel.

Thus, as aforesaid, the armature may move to set in operation theopening of the discharge valve 29, while circuit is closed to operatethe second relay 68 so that it closes the circuit 57], and closes thecontacts 74 to partially close the circuit 72b. Discharge may thuscontinue as long as the pushbutton 71 is held closing circuit 102, oreven if the operator may now release the pushbutton 71, since in thiscase the circuit continues completed through the contacts 70 in thecircuit 57], even after the pressure has fallen enough to cause thepressure sensitive switch 69 to open.

Thus to purge the vessel 10 after the pushbutton 71 has been released,or thereafter, or at any time, with the threeway switch 44 turned tomanual operation, (41a, 41b closed), it is only necessary to pushpushbutton 103 to close circuit with the circuit 72a to energize thelatching relay coil 52b, which, when energized, operates, as aforesaid,to close the circuit 45b and to break the circuit 57, whereby the purgevalve 35 is opened and the compressed air valve 106 and discharge valve29 are closed. Then, as the purge pressure diminishes the normallyclosed pressure sensitive switch 73 opens, and as the pressure fallsfurther to substantially atmospheric pressure, the contacts 51a of thepressure sensitive switch 50 close, and the pushbutton 45a may again bepushed to close the circuit 101 to admit material into the container 10.

Respective conduits 23b, 33b, 36b, 27b and 32b connect into therespective fill, materials delivery, purge, hot drying gas and ventvalve operator cylinders 23, 33, 36, 27 and 32, under respective pistonheads 23a, 33a, 36a, 27a and 32a, and respective conduits 23c, 33c, 36c,27c and 320 connect into such cylinders above the respective pistonheads therein. Thus, as shown in FIG. 1, conductor cords or sleeves 23d,33d, 36d, 27d and 32d for the respective conduits for the respectivevalve operator cylinders aforesaid, are provided to extend from thecontrol or panel box 40, where conventional instrument air, as from theinstrument air conduit 93, may pass through respective conventionalsolenoid actuated valves, not shown, as operated by the aforesaidsolenoids 48, 66 and 63, and sOlenoids 126 and 138, shown in FIG. 3, andto be hereinbelow described, these five solenoids admitting operativeair, gas or fluid, respectively into the conduits 23b or 230; into theconduits 27b or 270; and into the con- 36c; into the conduits 27b or270; and into the conduits 32b or 320; selectively to open or close theaforesaid fill valve 18, materials delivery valve 29, purge valve 35,hot drying gas valve 26 and vent valve 32.

As shown in FIG. 3, a light 49 is in circuit parallel with the solenoidcircuit 47 and the variable time delay relay circuit 46, and thus thelight 49 is on when the fill valve 18 is open; also a light 61 is in acircuit parallel with the solenoid circuit 59 which actuates the valve106 which admits the material activating gas, and with the solenoidcircuit 62 which closes the purge valve; and also a light 67 is in acircuit parallel with the solenoid circuit 65 which actuates the openingof the materials delivery valve 29. Additionally, a light 54 is shown ina circuit 53 which is completed when the latching relay 52 is actuatedto close the contacts 56a while the pressure within the container isstill high enough to maintain closed the contacts 51b of the pressuresenstive switch 50.

Thus, this occurs after the purge valve 35 has been reopened by openingof the latching relay contacts 56b, to permit the purging of thecontainer by the residual pressure therein until such pressure drops tosubstantially atmospheric so that the pressure sensitive switch 50 isactuated to open the contacts 51b and close the contacts 51a, therebybreaking the circuit 53 which contains the light 54 therein.

The lights 49, 61, 67 and 54 may have selectively differently coloredbulbs, as, respectively, green, blue, red and amber, thus to indicate,respectively, that filling, activating, discharging and purging aretaking place.

The respective valve operators 23, 27, 33, 32 and 36 may be used tooperate the respective fill valve 18, hot drying gas delivery valve 26,material delivery valve 29, vent valve 32 and purge valve 35, as shown,but it is often not necessary, in the case of light duty installations,and/ or in the case of the valves 26, 29, 31, 35, that special valveoperators be required for their operation. In such cases the solenoids60, 66 and 63, and the vent valve solenoid, to be hereinbelow described,may thus be connected directly to the respective valves 26, 29, 35 and31 to elfectuate their operation.

Also, as to the fail-safe feature of the vibrating paddle 38, thesensitivity of this feature is such that it can be regulated to operatealmost instantaneously as a container first starts to overfill, so thatthe relay 52a is energized to operate the latching relay 52 immediatelythe variable time delay relay 46 fails to function.

Additionally, as set forth hereinabove, the vibratory paddle 38 may beused instead of the variable time delay relay 46, as the primaryfunctional element to actuate the closure of the fill valve 18. In suchcase the sensitivity of the paddle 38 to adjustment, can determine thepromptness of sensitivity to material to close the relay switch 97.

In order to carry out a preliminary drying of material preparatory toactivating it and pressurizing it for discharge, as this inventionentails, additional apparatus and circuitry is provided for use with theapparatus and circuitry hereinabove described. Such additional inventivecircuitry and apparatus supports and controls the admission and cut offof drying air through the drying air valve 26, the venting of thecontainer during selective cycles through the vent valve 31, and theadmission of cut off of filter cleaning blast air through the air blastvalve 104, the valves 26, 31 and 104 being shown in relation to thecontainer 10 in FIG. 1.

Thus the double pole, single throw switch 60, shown in FIG. 3, may bemanually switched from closing circuit between the conductors 57 and57a, as shown in FIG. 3, to the dotted line position to close circuitbetween the aforesaid conductor 57, and a conductor 116 from which aseries or succession of parallel circuits extend to a conductor 118. Theconduit or conductor 118 in turn connects with a conductor 640 whichconnects with the junction of the conductors 64a, 64b, hereinabovedescribed, the conductor 640 in turn being connected to the neutral orpositive side conductor 41b, as aforesaid. The circuit or conductor 64chas a double pole, single throw switch 119 therein which is mechanicallyclosed by the closing of the fill valve 18, this operation beingindicated diagrammatically in FIG. 3 by a heavy dotted line connectingthe switch 119 and the solenoid 48 which operates the fill valveoperator 23 shown in FIG. 1.

A timer 120 of the well known Eagle type is provided in a circuitbetween the conductors 116, 118, which is adjusted to run for apredetermined time, at the end of which time it closes a normally openswitch 117 across the conductors 57a, 116, and opens a normally closedswitch 121 in the conductor 118.

A motor 122, which actuates the timer 120, is in cir cuit paralleltherewith, as shown in FIG. 3. Thus the motor 122 can be connected torun the timer 120 for the predetermined duration of the whole dryingperiod. A

light 123, which may be designated as a White light, is in circuitparallel with the timer circuit and its motor circuit 122 to indicatethat the drying process is in progress.

A solenoid winding circuit 124, in parallel with the circuits 120, 122,123 has a normally closed switch 125 therein; the solenoid winding 124actuating the aforesaid solenoid 126 which actuates the valve operator27 to open the hot drying gas valve 26. Also a solenoid winding circuit128, extends from the conductor 116 and includes a normally closedswitch 135 therein, the circuit 128 terminating at a contact 130, to behereinbelow described. The solenoid winding 128 when energized, actuatesa solenoid 129, to release air in a tube 142 to permit the filter blastair valve 104 to open.

Also, a timer circuit 131 extends from the conductor 116 parallel to thecircuit 128 and terminates at the contact 130, the timer 131 serving thepurpose of timing the brief opening of theair blast valve 104 betweenintervals of drying, as will be hereinbelow described.

Additionally a timer circuit 132 from the conductor 116 includes thetimer 132 therein and a normally closed switch 133 therein adjacent itsconnection to the conductor 118. Between the timer 132 and the normallyclosed switch 133, the pivot of a normally open switch 134 is connectedinto the circuit 132, which in closed position completes circuit to thecontact or junction of the circuits 128 and 131. The timer 132 servesthe purpose of timing the drying interval between successive opening ofthe blast air valve 104, the drying air entering continuously throughthe valve 106 between those brief instances when the blast air valve 104opens.

Also, the additional circuitry and apparatus comprised by the inventionincludes a solenoid winding circuit 136 between the conductors 116, 118,and also a relay circuit 137, parallel thereto. The circuit 136 actuatesa solenoid 138 which in turn actuates the valve operator 32 whichcontrols the opening and closing of the vent valve 31, shown in FIG. 1.

The Eagle timer 120 is set, as aforesaid, to run for the duration of thepreselected and preset drying cycle and then times out to close thenormally open switch 117 and to open the normally closed switch 121. TheEagle timer cycle is divided into a number of sub-cycles, during each ofwhich the drying air is delivered for an interval and then for aninstant the drying air is shut off and blast air enters the top 12a ofthe shell to blow reversely through the filters 114 and through thecentral filter 112 to blow any material grains or particles impinged onthe inner surfaces thereof back into the material plenum 15. Thus, ineach sub-cycle the drying air timer 132 times out to open the normallyopen switch 125 to break the solenoid circuit 124, whereby the solenoid126 closes the drying air valve 26, the timer 132 at the same timeclosing the normally open switch 134 to start the blast air timer 131and to close the blast air solenoid circuit 128, whereby the solenoid129 opens the blast air valve 104.

The timer 131 then runs to time out to open the normally closed switchto the solenoid winding 128 whereby the solenoid 129 opens the blast airvalve 104 and opens the double pole, single throw or relay switch 133,thus breaking the circuit to both timers. Both the timer 131 and thetimer 132 may now reset, the timer 131 taking power off the normallyclosed switch 135 to permit the solenoid circuit 128 to be restored andtaking power off the relay switch 133, allowing it to open. Also, thetimer 132 takes power off the normally open switch 134, permitting it toopen, and takes power off the normally closed switch 125 in the solenoidwinding circuit 124, allowing this normally closed switch 125 to close,whereby the solenoid 126 may open the drying air valve 26. With thetimers 131 and 132 both reset, the drying air valve 26 is opened for itssub-cycle of drying air delivery, followed by discontinuation for filterair back blast, as aforesaid.

When the drying air-blast air sub-cycles have been repeated *for a totalamount of time equal to the time for which the Eagle or control timer120 has been set, this timer times out, opneing the switch 121 andclosing the switch 117, as aforesaid. During the drying process therelay 137 has been energized to move the respective switches 62a, 62b incontact with the repsective contacts 64d, 64s, thus keeping the winding62 of the solenoid 63 energized whereby the solenoid 63 has held thevalve operator 36 in purge valve closing position. At the end of thedrying process the relay 137 is de-energized to switch the switches 62a,62b into the position shown in FIG. 3, thus to complete the purgesolenoid winding circuit 62 to the switch 64, which is closed to beginthe activation and transfer of material steps, as hereinabove described,the purge valve 35 thereby remaining closed after the switch 64 isclosed, until it opens to start the purge step.

The closing of the switch 117 throws the apparatus directly into theactivation and transfer step, while the opening of the switch 121 breakscircuit to the apparatus functioning in the drying cycles, and thisapparatus and circuitry remains inactive until the next closing of thefill valve 18 mechanically closes the shift switch 119. Then, with theswitch 117 closed, the apparatus immediately embarks into the steps ofactivating the material, discharging it, purges the vessel, andreturning to initial conditions, as hereinabove described.

By a skillful combination of circuitry and apparatus the processing maybe carried out with both uniformity and alacrity, and within thefineness of detail permitted by the many features through whichadjustment may be made. The materials processed, for instance, may covera wide range of pharmaceutical components, plastics, foods, and thelike, which enter with various proportions of moisture therein. Thephysical form of the material handled may be granular, crystalline, orpowdered, as examples, in micron size particles up to from to 20 mesh.The diaphragm separating the gas and material plenums should best be of200 mesh woven, stainless steel, or of porous ceramic. Fineness of themembrane may be controlled by employing successive layers thereof. As tothe angle at which the membrane may be installed, this may be varied byvirtue of the type of material used, and by the moisture content, andthe slope may range from 5 degrees to say degrees. Also, the filterrequirements may vary, it having been found that filters which provide atotal filtering area in 15 to 1 ratio to the bed area of material is asatisfactory ratio, but this ratio may vary, as say from to 1 to 10 to1.

The apparatus and methods disclosed hereinabove, and hereinbelowclaimed, are not all inclusive, as set forth, including as portrayed inthe drawings, and other combinations of structure, circuitry and methodsof employing the invention may be considered as falling within the fourcorners of the herein invention, as long as such also fall within thebroad spirit of the invention, and Within the broad scope ofinterpretation claimed for and merited by the appended claims.

What is claimed is:

1. Material drying and transporting apparatus comprising a pressurevessel, a gas permeable membrane across said vessel separating alowermost gas plenum from a central, material plenum thereabove, a fillvalve to admit material batches into said material plenum to be driedand transported, a valve controlled drying gas delivery conduit intosaid gas plenum, a vent valve from said material plenum, a valvecontrolled, pressurized gas conduit into said gas plenum, a pressuresensitive valve controlled discharge conduit from said material plenum,and automatically operable circuitry sequently functional to open saidfull valve, to close said fill valve and to open said drying gas valveand said vent valve, to close said drying gas valve and said vent valveand to open said pressurized gas valve to activate the dried materialinto a flowable state and to build up a pressure in said vessel to opensaid discharge valve whereby said materials are discharged through saiddischarge conduit, said discharge valve opening responsive to pressuredrop, and upon further ressure drop said apparatus being restored toinitial status automatically to repeat the handling of a succeedingbatch of material.

2. Material drying and transporting apparatus as claimed in claim 1which additionally includes a pressure sensitive valve controlled, purgeby-pass conduit from said material plenum to said discharge conduitdownstream of said discharge valve, said purge valve being opened bysaid circuitry responsive to the pressure drop which closes saiddischarge valve whereby said material is purge discharged by residualpressure in said vessel until said apparatus is restored to initialstatus, as aforesaid.

3. Material drying and transporting apparatus as claimed in claim 1which additionally includes a filter means around the fill valve inletand-between the fill valve inlet and the interior of said vessel andabove the material, whereby to filter the drying gas on its way to saidvent.

4. Material drying and transporting apparatus as claimed in claim 1which additionally includes a baffle across the vessel below the ventand above the material, in which said fill valve includes an inlet spoutwith lower end comprising a filter opening centrally through saidbafile, in which a plurality of filters opening downwardly through saidbafile are provided around said central filter, said apparatusadditionally including a valve controlled filter blast gas conduit intosaid vessel above said filters, and in which said circuitry is operableintermittently to interrupt drying gas delivery to admit filter blastgas to back clean said filters.

5. Material drying and transporting apparatus comprising a pressurevessel, a gas permeable diaphragm across said vessel separating alowermost gas plenum from a central material plenum thereabove, a bafileacross said vessel separating said material plenum from a filter blastand drying gas uppermost plenum, a fill valve to admit material into thetop of said vessel including a delivery spout with lower part comprisinga central filter and opening downwardly through said bafiie, a pluralityof filters spaced about said central filter and opening downwardlythrough said bafiie, a valve controlled drying gas delivery conduit intosaid gas plenum, a valve controlled filter blast gas conduit into saiduppermost plenum, a vent valve from said uppermost plenum, a valvecontrolled pressurized gas conduit into said gas plenum, a pressuresensitive valve controlled discharge conduit from said material plenum,a pressure sensitive valve controlled purge by-pass conduit from saidmaterial plenum to said discharge conduit downstream of said dischargevalve, and automatically operable circuitry sequentially functional toopen said fill valve, to close said fill valve and said purge valve andto open said vent valve, and in sub-cycles, successively to open andclose said drying gas valve to dry said material, and said filter blastvalve to back-clean said filters, and then to close said vent valve,said drying gas valve, said filter blast gas valve and said purge and toopen said pressurized gas valve to activate said dried material to apressure to open said discharge valve to discharge said dried materialsuntil the vessel pressure drops to close said discharge valve and opensaid purge valve whereby said material is purged by diminishing residualpressure until the vessel pressure drops to substantially atmospheric tostart a succeeding cycle, as aforesaid.

6. Material drying and transporting apparatus as claimed in claim 1,which additionally includes compressor means to supply drying gas,filter blast gas, and pressurized activating gas as compressed air.

7. The method of automatically drying and transporting materialcomprising the steps of admitting the material as a predetermined batchinto a defined space providing a gas plenum below a material plenum,passing drying gas into the gas plenum to pass through a perforatediaphragm supporting the material and through the material to be ventedfrom the material plenum, discontinuing the drying gas admission andclosing the vent and admitting pressurized gas into the gas plenum topass through the membrane to activate the dried material and to achievea predetermined pressure in the vessel thereby to open the materialplenum to discharge, and full discharging the material responsive to thepressure built up in the space until the pressure falls to apredetermined value to actuate the discontinuation of pressurizing gasadmission, and restoring initial conditions for the receipt of asucceeding batch of material into the defined space.

8. The method as claimed in claim 7 which includes the additional stepof using the residual pressure in the defined space immediately afterdiscontinuation of full discharge to purge the material plenum as thepressure falls to substantially atmospheric prior to restoration ofinitial conditions as aforesaid.

9. The method as claimed in claim 7 which includes the additional stepof filtering the drying gas between the material and the vent.

10. The method as claimed in claim 7 which includes the additional stepsof filtering the drying gas of material particles on its Way to the ventwhile repeatedly interrupting the drying gas supply by injecting gasblasts above the filter means to back-clean the filter means.

11. The method as claimed in claim 7 which includes the additional stepof filtering the drying gas of material particles on its way to the ventwhile repeatedly interrupting the drying gas supply by injecting gasblasts above the filter means to back-clean the filter means, the blastgas supply being discontinued when the drying gas supply isdiscontinued, the further additional step being included of usingresidual pressure in the defined space immediately after discontinuationof full discharge to purge the material plenum as the pressure falls tosubstantially atmospheric prior to restoration of initial conditions, asaforesaid, the drying gas and the blast gas being pre-heated, and thedrying gas, blast gas, and pressurized gas for activation eachcomprising compressed air.

12. Material drying and transporting apparatus comprising a pressurevessel including a gas permeable membrane bridging the lower part ofsaid vessel above the bottom thereof and dividing it into a materialplenum thereabove and a gas plenum therebelow, a fill valve to admitflowable material through the top of said vessel into said materialplenum to upstand from said membrane, a compressed gas inlet valve intosaid gas plenum, a discharge valve controlled discharge conduit withdischarge valve disposed in the upper part of said material plenum, apurge valve controlled by-pass conduit with purge valve disposed in theupper part of said material plenum adjacent said discharge valve, apressure sensitive control means, and circuitry including said controlmeans and automatically operable sequentially to open said fill valve,to close said fill valve, then to close said purge valve while openingsaid gas inlet valve to admit pressurized gas substantially uniformlythrough said membrane and to activate said material to a high state asthe pressure rises in excess of a pressure sensitive means high controlpressure fully to open said discharge valve for said material to passupwardly and onward through said discharge valve and outwardly throughsaid discharge conduit, as the pressure falls below a pressure sensitivemeans lower control pressure fully to close said discharge valve andsaid gas inlet valve and to open said purge valve, the residualcompressed gas purging upwardly through said purge valve and saidby-pass conduit and on outwardly through said discharge conduit, thepressure falling to approximately atmospheric whereby to open said fillvalve, as aforesaid, said pressure vessel also including a valvecontrolled drying gas delivery conduit into said gas plenum and a ventvalve from said material plenum, said circuitry also including meansoperable, along with the closing of said fill valve and of said purgevalve, to open said drying gas valve and said vent valve, then to closesaid drying gas valve and said vent valve prior to the closing of saidpurge valve and the opening of said gas inlet valve, as aforesaid.

References Cited UNITED STATES PATENTS 2,799,947 7/1957 Elwess 34152,916,831 12/1959 McCash 34-57 3,186,102 6/1965 Brociner et al 34-56 XR3,392,456 7/1968 Rainville 3456 KENNETH W. SPRAGUE, Primary Examiner.

' US. Cl. X.R. 34-15, 57

